The University of Pennsylvania Medical Scientist Training Program provides support for both MD-PhD and VMD-PhD trainees and is currently in its 37th year of funding. The primary goal of the program is to identify, train and mentor a diverse group of outstanding men and women who will become the leaders of biomedical human and veterinary research, as well as teachers and scholars. To accomplish this goal, we have established flexible training plans that emphasize the integration of the professional and research degrees in preparation for careers that will make use of both. The large institutional commitment to this goal is reflected by the investment that the medical and veterinary schools have made in this program, providing it with resources that are used to help cover tuition and stipend costs, maintain enrichment activities, and support administration of the program. There are currently 220 combined degree students (185 MD-PhD and 25 VMD-PhD), all of whom are fully funded. Admission is open to recent college graduates and to current Penn MD, VMD and PhD students. Selection emphasizes academic excellence, research experience, creativity, letters of recommendation and a well-articulated plan for a career in research. Most trainees do graduate work in the biomedical sciences, but 17% are currently taking advantage of the breadth of opportunities offered by a large university by enrolling in graduate programs in Biomedical Engineering, Physics, Health Care Economics, History & Sociology of Science, Medical Anthropology, Urban Design, and Epidemiology. The proposed training faculty reflects this diversity of interests. It includes 147 senior and junior PhD, MD-PhD and MD investigators in departments, centers and institutes spread across Penn's campus. As of June 2011, there have been 442 MD-PhD and 63 VMD-PhD graduates since program inception. 76% of MD-PhD alumni and 87% of VMD-PhD alumni who have completed postgraduate training are employed by academic centers, research institutes, the biotech and pharmaceutical industries or federal agencies. Many have NIH or other extramural funding for their research. The average time to completion for recent graduates in both programs has been 8 years. The attrition rate for the past 10 years has been low: 4% in the MD-PhD program and 8% in the VMD-PhD program. Specific goals for the next 5 years include 1) continued growth to achieve at least 200 MD-PhD and 30 VMD-PhD students, 2) expanded partnerships with additional graduate programs at Penn, 3) further integration of the graduate and professional degrees, 4) reducing time to degree without compromising training, and 5) attracting and training a diverse group of individuals who will be prepared for the discovery and application of new knowledge through basic, translational and patient-oriented research.